For a long time, it was thought that hyenas were hermaphrodites. But now we know that isn’t the case. Hyenas are the only mammal that don’t have an external vaginal opening. Instead, females urinate, copulate and give birth through a remarkable pseudo-penis. (It’s a bit like squeezing an actual penis through a pair of panties.) And while the function of this “penis” is still unclear, it may be a means of protecting females from male sexual aggression.
This incredible organ also explains how it is possible for a spotted hyena mother to have multiple offspring in one pregnancy. The first born cubs are fetuses that develop inside the uterus, with no external birth canal, and they then enter the world through the pseudo-penis.
The fetuses are then able to take in and digest their own nutrients without interference from the mother. The result is that a single pregnancy can produce up to six cubs.
Despite their aggressive, scavenging ways, hyenas are very caring parents. They nurse their young for a long time, and the mothers will even bring prey back to the den for the babies to feed on.
Spotted hyenas have a gestation period of 90 days, and each litter contains between two and four cubs. The 1-1.5 kg cubs are born through a birth canal that resembles the genitalia of a male hyena, and is actually the female’s clitoris. This extraordinary mimicry is believed to have arisen because males were more aggressive than females during hyena evolution, and so females began imitating their appearance and genitalia in order to be more successful at passing on their genes.